Improvement in the construction of tunnels and sewers



-.TNITEIJ STATES PATENT OFFICE.

GEORGE IINOLL, OF sAN FRANCIsCo, CALIFORNIA.

IMPROVEMENT IN THE CONSTRUCTION OF TUNNELS AND SEWERS.

Specification forming part of Letters Patent No. 144,112, dated October28, 1873; application filed January 17, 1873. i

To all 07mm 'it may concern.' Y

Be it known that I, GEORGE KNOLL, of the city and county of SanFrancisco, State of California, have invented certain Improvements inthe Construction of Tunnels, Sewers, and other arched buildings, ofwhich the following is a specification:

(l.) The iirst part of my invention relates to the construction of asewer, tunnel, or other arched building, with tongued or grooved brickspressed to a certain regular shape and curvature, with holes piercedthrough them for connecting-rods of wood or iron to run into and bindtogether in such manner that the said bricks can be placed in theirorder, one upon another, so as to produce a self-sustaining work, and,when the conformation is completed, form a tunnel of great strength,requiring no name-work during its Vconstruction, and little or no mortarwhen placed in hard grounds, thus insuring a great saving in time,labor, and expense.

(2.) The second part of my invention relates to the construction ofmetallic adjustable straps placed transversely across the tunnel orsewer so as to answer the purpose of supports for such gas, water, orother main pipes as may be laid within the tunnel, and at the same timeserve as braces for the structure itself.

Figure/1 is a vertical transverse section of a sewer embodying myinvention. Fig. 2 is a longitudinal elevation of Fig. l with a portionin section. Fig. 4 is a perspective view of one of the adjustable bracesfor supporting the vmain pipes and strengthening the tunnel. Fig. 5 isaperspective view of a sample brick, tongued, grooved, and pierced,embodying my invention.

S S represent a sewer or tunnel. B B are the bricks composing it, whichare made of the same dimensions and of the same pattern, with theexception of the two or three, B B', forming the walls between thesemicircular roof and iiooring ct c and a. c', respectively. Thesebricks before being baked are pressed or stamped and numbered for thecurvature required, so as to have a smooth face, f, on which the numberis impressed, a tongue on one edge, t, and a groove, g, on the oppositeside. A hole, h, is at the same time pierced through each to serve thedouble purpose of holding the connectingrods r, ofwood or iron, forbinding several together, as also to insure a more thoroughly-bakedbrick, as'

well as allow of a free circulation of air in all construction s whereinsuch bricks may be used.

In building the structure, the bricks are placed one upon another,edgewise, in a sloping direction, as shown in Fig. 2, so that the grooveof each brick sha-ll hold half of the tongues of the two anterior ones,and, consequently, the tongue of eachfits into the half of each grooveof the two succeeding bricks. In hard ground it is only necessary forthe workman to pile up these bricks as fast as he can handle them,without the employment of any mortar, excepting in the case of a tunnelbeing used as a sewer-such as S-when an .inner layer of mortar for theflooring, to make all water-tight, may be required.

G C are the cast-iron braces for supporting the main pipes for water, W,and gas, G, &c., and for strengthening the tunnel. They are composed oftwo pieces, c and c', each of which is provided with projecting bands bb at one end for inclosing the brick-work of the tunnel in the spacesbetween them, and around the neck n, which rests on the structure.tremities of these pieces slots m are made for holding bolts q q', sothat the compound brace C or C can be adjusted to suit the dimensionstransversely of the tunnel. The piece c has curved portions z z for themains to rest ou, and a projection, y, in the center for an eye, c, tobe screwed into, so that a pulley can be hooked onto it and suspendedtherefrom.

Forlaying the mains W, G, Src., the open-V ings or shafts leading to thesewer are inclined so as to have a convenient grade for lowering' andshifting the pipes along and within them. A truck, T, for carrying thesepipes, is provided with wheels having curved faces to suit the formationof the base of the tunnel, and is moved along from place to place bypower applied to a windlass iixed at any one of the openings or shafts,the windlass-rope d being attached to the truck, and running over two ormore pulleys, such as K, suspended from the braces C C.

I claim as my invention-- Near the eX- 1. The' structure S, built withnumbered bricks B B', through the bodies of which rods or tubes r r arerun longitudinally so as to string several together for pres erving theshape of the structure, substantially as und for the purpose herein setforth.

2. The compound adjustable braces C, provided With necks n n, zmges bb', und curvatures z' z', in combination with the tongued and groovedbricks B B' and longitudinal rods r r, substantially as and for thepurpose hereinbefore set forth.

GEORGE KNOLL. Witnesses:

ALFRED C. CRANE, LIONEL VARIoAs.

